In communication networks, there is always a challenge to obtain good performance and capacity for a given communications protocol, its parameters and the physical environment in which the communication network is deployed.
In a wireless communications network wireless radio terminals communicate via a Radio Access Network (RAN) to one or more core networks. The radio terminals may e.g. be a mobile station (MS) or a user equipment unit (UE) or similar, e.g. such as mobile telephones also known as “cellular” telephones, and laptops with wireless capability, and thus can be, for example, portable, pocket, hand-held, computer-comprised, or car-mounted mobile devices which communicate voice and/or data with radio access network.
A wireless network, illustratively a Long Term Evolution (LTE) communications network, may comprise groups of mobile telephones or other user equipment (UE) communicating with one or more eNodeBs, which communicate with one or more Serving Gateways (SGWs), which communicate with a Packet Data Network (PDN) Gateway (PGW), which communicates with fixed networks such as Internet Protocol (IP) Multimedia Subsystem (IMS) access networks or core networks. Additionally, the LTE network includes various network elements such as Mobility Management Entities (MMEs), a Policy and Charging Rules Function (PCRF), a network management system (NMS) and so on.
For example, the General Packet Radio Service (GPRS) is a wireless communication system, which evolved from the GSM. The GSM EDGE Radio Access Network (GERAN) is a radio access network for enabling radio terminals to communicate with one or more core networks. A UE or a MS may interact with GPRS using the GERAN radio access and the UTRAN radio access. The UE-related and/or MS-related control signaling is handled by the Serving GPRS Support Node (SGSN) with support of subscription information provided by the Home Subscriber Server (HSS).
An Access Point Name (APN) is the name of a gateway between a GPRS (or 3GPP, etc) mobile network and another computer network, frequently the public Internet. The PDN gateway (commonly denoted PDN GW or PGW) of a PDN connection for a certain APN is determined by a mechanism called APN resolution. APN resolution is the process of Domain Name System (DNS) look up to determine the IP address of the PDN-GW that provides connectivity to the PDN identified by the APN. When a UE initiates a new PDN connection, it provides the APN to which it wants to connect to in the initial UE request sent to the network. The SGSN or the MME (depending on if the access is LTE or UTRAN/GERAN) checks the provided APN against the user subscription record it has previously obtained from the HLR/HSS when the UE/MS first attached, and then sends a recursive DNS Query to a DNS server that returns the PDN-GW IP address.
It some scenarios it is desired, or even necessary, to force all active sessions of a single user or a group of users to go through the same mobile core GW.
Hence, there is still a need for an improved GW selection.